Electrical assembly



14:.wirbu March 6, 1962 EB. MITCHELL ETAL 3,024,335

ELECTRICAL ASSEMBLY Filed Oct. 28, 1958 i /4 44 5'0 2% a 6 'Imven 202".

Edwcu if B. Mzlilcheii 54 Wiliam H. I ina 1 90K Patented Mar. 6, 1962 a it ware

Filed Oct. 28, 1958, Ser. No. 770,155 2 Claims. (Cl. 260-466) This invention relates generally to electrical switches and in particular to a miniature switch for use in electronic circuits.

Due to recent advances in the electronic industry great emphasis has been placed on miniaturizing electronic apparatus for hitherto unknown applications. For example, in communication equipment, two way radios have been developed in which both the transmitter and receiver are contained within a single unit, the unit being compact and light to enable it to be carried on or about the individual. Consequently, a need has developed for miniature switching apparatus which will effectively make and break the circuit to alternate between transmission and reception at the operators discretion. Due to variables that exist in positioning the apparatus the contacts utilized in the switch mechanism must be of a type that will make contact without danger of intermittency regardless of the angular pressure applied to the plunger.

The object of this invention is to provide a miniature switch assembly having contact members that will pivot about an axis to insure continuity.

A further object of this invention is to provide a simple, inexpensive miniature switch assembly which may be adapted for use in communication equipment carried by an individual.

Other objects of the invention will, in part, be obvious, and will, in part, appear hereinafter.

In the drawings:

FIG. 1 is an exploded view in perspective of the switch assembly;

PEG. 2 is a bottom plan view of the switch assembly;

PEG. 3 is an enlarged view in section taken on line 33 of FIG. 2;

FIG. 4 is an enlarged view in section taken on line 4 l of PEG. 2 showing the moveable contacts canted by angular axial pressure; and

FIG. 5 is a view in section taken on line 5-5 of FIG. 3 with the contacts in the normal position.

Referring to the drawings, there is illustrated a switch it which is adapted for assembly onto a panel 12. The switch comprises generally an insulated housing 14 having terminals 16 extending through the bottom wall 18 with fixed contact means 2d bent over to retain them firmly in position, and a guide means 21 extending through the bottom wall it and substantially perpendicular thereto. A second housing 9.2 with an inner diameter slightly larger than the first housing and adapted for telescopic engagement with the first housing 14 and having an externally threaded bushing 24 extending axially from the closed end 26 for attachment to the panel 12 and a plurality of prongs 28 extending from the open end 39 of the housing 22.. Disposed intermediate the two housings 14 and 22 is an insulated contact carrier 32 having an integrally molded plunger 34 extending axially from one surface and positioning guide 36 extending axially from the other surface. Slots 33 are formed adjacent the peripheral edge 46 of the contact carrier 32 having apertures 42 extending through to the other side. Floating contacts 44 having springs 41-6 to normally bias the contacts away from the carrier 32 are assembled within the aperture 4-2 by forcing a tapered head 58 having a maximum diameter slightly greater than the diameter of the aperture 42. The contact carrier 32 is formed of a sufiiciently resilient plastic so that it will expand to accommodate the tapered head and then return to retain the contact in assembly. The shank portion Si) is of a diameter less than the diameter of the aperture 4-2 to allow the contact to move axially with respect to the carrier 32 and to allow a certain amount of canting. An enlarged head portion 52 is formed on the distal end of the contact 44 which serves to retain the spring 4-6 in assembly and to complete the electrical circuit when the plunger is depressed by the plunger 34.

As it will readily be seen, the switch components can be readily assembled with the floating contacts 44 axially aligned with the fixed contacts 20 by means of a key 54 formed integral with the housing 14, adapted for axial sliding engagement with a key way 56 formed on the peripheral edge 48 of the contact carrier 32.

The operation of the switch is in the conventional manner in that axial movement of the plunger 34 compresses the spring 58 so that it forces the contact carrier 32 in the direction of the fixed contacts 20 in such a manner that the floating contacts 44 will make contact and canting of the plunger will be compensated by the springs 46 and prevent intermittency.

Since certain other obvious modifications may be made in this device without departing from the scope of the invention, it is intended that all matter contained herein be interpreted in an illustrative and not in a limiting sense.

We claim:

1. An electric switch assembly comprising an insulated housing with fixed internal strip contacts assembled therein and solder lug terminals exterior thereof, an insulated disc carrying a plurality of independent spring projected contacts adjacent the periphery, said contacts each having a flat base portion connected by a shank about which a coil spring is assembled to a frusto-conical retaining head, said shank being freely reciprocable through an aperture in said disc portion, each of said independent spring projected contacts bridging two strip contacts, a guide member carried by said disc extending axially in the direction of said housing for cooperative engagement with a guide cavity, spring means positioned within said guide cavity bearing against said guide member to bias the switch to open position, a plunger extending in a direction opposite to said guide member and a mounting cap surrounding said plunger and enclosing said assembly.

2. An electric switch comprising a fixed housing with a closed guide cavity extending axially from one end and fixed contact members assembled therewith, and an axially moveable contact carrier disposed between said housings comprising an insulated disc carrying a plurality of independent spring projected contacts, said contacts having a frusto-conical head portion and a flat portion at the 0pposite end with a shank disposed intermediate thereof, said shank being freely reciprocable within said carrier by spring means assembled concentrically therewith, said independent spring projected contacts bridging the fixed contacts assembled within said first housing and axially spaced therefrom, actuating plunger means formed integral with said carrier extending through said second housing, said carrier being spring biased in the direction of said plunger by a spring disposed within said closed guide cavity.

References Cited in the file of this patent UNITED STATES PATENTS 2,367,657 Boersma Jan. 23, 1945 2,519,329 Woodward Aug. 15, 1950 2,699,960 Callery et al Jan. 18, 1955 2,794,086 Barrett May 28, 1957 2,859,296 Neu Nov. 4, 1958 FOREIGN PATENTS 540,366 Great Britain Nov. 3, 1941 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,024,335 March 6, 1962 Edward B. Mitchell et a1.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 1, line 47, after "position." insert FIG. 6

is a view in section taken on line 6-6 of FIG. 4.

Signed ,end sealed this 3rd day of July 1962.

(SEAL) Atteet:

ERNEST w. SWIDER DAVID LADD Anesting Officer Commissioner of Patents 

